Plate for making stencil-sheets.



PATENTED NOV. 29, 1904.

- v G. I. HERRIGK.

PLATE FOR. MAKING STENCIL SHEETS.

APPLICATION FILED FEB 2, 1904.

N0 MODEL.

. IF mmvl/ W A "5mm" W' 24? r i A lvihlcmca 7 v U ITED STATES Patented November 29, 1904.

PATENT OFFICE.

PLATE FOR MAKING STENCIL-SHEETS.

SPECIFICATION forming part of Letters Patent No. 776,180, dated November 29, 1904.

Application filed February 2, 1904. Serial No. 191,670. (No model.)

To all whom it may concern:

Be it known that I, GEORGE IRA HERRIOK, a citizen of the United States, residing at more particularly to that kind of stencil plates which are used in making autographic' stencils for the reproduction of drawingscontaining circles, radii, and tangents to circles by the mimeographic process, the special object of this invention being to form a plate for making stencil-plates with spiral grooves thereon. v

Heretofore with stencil -plates that have been engraved or stamped with a series of straight lines it has been difficult to draw circles and their radii, owing to the fact that at four points upon the circumference of a circle there will be points of tangency to the grooves of a plate engraved with a double series of straight lines, and there will be four radii, the drawing of which is impossible with a straight-line-grooved plate, since the stylus will follow in these grooves and cause the ruination of the stencil-paper.

The present invention is for the, purpose of avoiding this difficulty and making it possible to draw circles, radii to circles, and tangents to circles with ease and facility, the plate being engraved with spirals and so constructed that no circle which is larger than the inner circle of the plate will have points of tangency to any groove.

The advantages and the structure of the stencil-plate will appear more particularly in the following detailed description and may be seen upon reference to the accompanying drawings, in which Figure 1 is a plan view' of the stencil-plate. Fig. 2 is a section on spirals A A and B B before the spirals D A and C B are got. Fig. 3 is a section on spirals A A and B B after the getting of spirals D A and C B and others,

including supplementary spirals. Fig. A is a section. of the plate on line G G.

Referring more particularly to the drawings, P is a stencil-plate consisting of a flat piece of metal upon which is engraved or stamped spiral curvessuch as A A, B B, C B, DA, and others. One end of each of said curves is tangent to the inner circle H, each spiral being placed upon the plate as a radial spiral. The inner circle H includes a soft piece of wood or horn, Which provides a suitable material upon which to place the needle-point of a compass, which is illustrated and indicated at 1). If it is so desired, the

interior of the circle H may alsobe provided -with spirals; but itis preferable in actual use to provide the interior of the circle with the material described.

-. On account of thefact of the outer end of the spirals A, B, C, and D occupying a larger angular opening than at the innerportion near the circle H supplementary spirals, before referred to, are provided, which are practically parallel to the original spirals-as, for instance, A Abut which extend only a portion of the distance and give the effect indicated at E, which will result in there being a series of fine radial spirals cut in the plate at certain fixed distances apart, according to the proportions of the original spiral. When the same operation is gone through with with the spirals D, A, and others, a similar effect is gotten, as illustrated and referred to above and indicated at-F. The result of this is a seriesof spirals and supplementary spirals crossing each other, as shown at F, and produces the effect upon the plate of a number of small diamonds, which are, as is readily understood, 'of extremely small area after the division of the plate in the manner before described. The manner'of using this plate as provided with these spiral grooves cut into the face of the same is the ordinary process common in the art of rnimeographing and consists simply in placing'a slab of soft paper or other material upon the plate and the drawing, for instance, to be reproduced upon the soft paper, the lines thereof being made by a person using a stylus. The result as due to the present invention is that curves of all natures may be easily reproduced, due to the difierent circles possible to be made and the tangents and radii thereof which can be easily drawn. This result is new, as has been before stated, since it has only been possible heretofore to reproduce straight lines with any accuracy and surety.

Therefore what I claim, and desire to seizure protection on by Letters Patent, is as foloWs:

1. As a new article of manufacture, a plate for producing a stencil-sheet having its face provided with a plurality of spiral grooves radiating from a common central circle, substantially as set forth.

2. A plate for producing a stencil-sheet having a series of substantially parallel spiral grooves formed in the face thereof radiating from the center of the plate, whereby circles and their curves may be reproduced by a mimeographic process, substantially as set forth.

3. A plate for making stencil-sheets comprising a body portion having a series of spiral parallel grooves formed in the face thereof and a central circle from Which said grooves radiate, substantially as described.

4. A stencil-plate of the type set forth having a central inner circle provided With a soft material Within the same, and a series of intersecting spiral grooves formed in the face of the plate and radiating from said circle.

5. A plate for producing stencil-plates comprising a series of intersecting spiral grooves formed in the face of the plate and radiating from a central circle Within the plate, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

' GEORGE IRA HERRICK.

W'itnesses:

JOHN H. HERRICK, RALPH L. HERRICK. 

